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ProfHewitt
searching PlanetScale…
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31.
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ProfHewitt
5y ago
Messages themselves should be Actors.
32.
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ProfHewitt
5y ago
Excellent video by Dan Ingalls on the Xerox early history of Smalltalk. In November 1972, Alan Kay gave an inspiring seminar at MIT on Smalltalk-72. There were ongoing discussions during the weeks after the lecture about the following:
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ProfHewitt
5y ago
It's useful enough to have gained an effective monopoly. However, it cannot be relied upon in specific instances.
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ProfHewitt
5y ago
Unfortunately, Wikipedia is often not a reliable source of information because its articles are posted and maintained by largely unaccountable anonymous parties.
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ProfHewitt
5y ago
Dear Jørgen Veisdal: Fair enough. But it would be helpful if the article could be updated to get some information corrected as pointed out in other posts on this page.
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ProfHewitt
5y ago
History of the people involved is indeed very interesting. Particularly recommend the BBC2 film "Dangerous Knowledge". BTW: The article "Turing Uncomputability" got some of the history wrong about the 1930 interaction b
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ProfHewitt
5y ago
The [Church 1935] proof of the computational undecidability of the halting problem is essentially the same as the [Turing 1936] proof. Consequently, the article under discussion would be better titled "Church/Turing Uncomputabili
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ProfHewitt
5y ago
Unfortunately, the article "Turing Uncomputability" is incorrect that [Gödel, 1931] was first to prove inferential undecidablity of mathematical foundations. The [Gödel, 1931] proof using the proposition I'mUnprovable is
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ProfHewitt
5y ago
The Church/Turing Hypothesis is false because there are digital computations that cannot be performed by a Nondeterministic Turing Machine . For example, see the following: https://papers.ssrn.com/abstract=3603021
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ProfHewitt
5y ago
"Event-driven architecture" only considers a small subset of the computational events fundamental to understanding computation. Actor Theory is based on automatizing the "precedes" partial order for all computational e
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ProfHewitt
5y ago
Sets initially seemed appealing because they are less abstract than types. However, the lack of abstraction turned out to be a fatal flaw in attempts to make sets the foundations of mathematics because: * sets cannot be rigorously def
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ProfHewitt
5y ago
BoiledCabbage: You are on the right track! [Dedekind 1888] started out on the correct path by defining natural numbers up to a unique isomorphism. Unfortunately, there was long detour through 1st-order logic :-( Powerful foundations are now
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ProfHewitt
5y ago
Orthodoxy in science works until the next paradigm shift. See "In retrospect: The Structure of Scientific Revolutions" https://www.nature.com/articles/484164a
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ProfHewitt
5y ago
Unfortunately, 1st-order ZFC has very severe limitations because it does not precisely define sets. However, ordinals that provide the backbone of sets have been precisely defined up to a unique isomorphism using types. See the following ar
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ProfHewitt
5y ago
Types are about rigorously constructing mathematical abstractions from primitive types defined up to a unique isomorphism. In fact, types have become the primary foundation of Computer Science. Russell introduced the crucial concept of the
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ProfHewitt
5y ago
Note that forcing and the independence results are only for 1st-order logic . They do not work for theories that characterize mathematical abstractions such as the Ordinals and Natural Numbers up to a unique isomorphism. See the followin
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ProfHewitt
5y ago
Lawvere's work is elegant! However, Lawvere missed the crucial importance of Russell's orders on propositions in blocking the construction of monster propositions using recursive definitions . Orders on propositions block constru
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ProfHewitt
5y ago
PS. There are no ordinals of intermediate cardinality between ω<sub>0</sub> and ω<sub>1</sub>.
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ProfHewitt
5y ago
The results in the article are based on 1st-order logic, which is inadequate for the foundations of mathematics. Mathematical abstractions need to be characterized up a unique isomorphism as in the theory Ordinals described in the following
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ProfHewitt
5y ago
Unfortunately, a theoretical embedding doesn't always accomplish the work of Double Negation Elimination in practice.
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ProfHewitt
5y ago
Constructivism is based on intuitionistic logic, which lacks some important logical principles. For example, it lacks the following principles: * excluded middle * double negation elimination The principles can be valuable f
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ProfHewitt
5y ago
The Howard-Curry correspondence does not help proving properties of concurrent systems. Instead, need to use Actor Event induction: https://papers.ssrn.com/abstract=3418003
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ProfHewitt
5y ago
Foundations of mathematics are inferentially incomplete, that, is, there are true but unprovable propositions (although [Gödel 1934] results do not hold for foundations). See following for a proof: https://papers.ssrn.com/
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ProfHewitt
5y ago
Joker_vD: Looks like you are incorrect because Func and FuncToFunc are defined recursively.
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ProfHewitt
5y ago
Is FuncToFunc defined recursively in the excerpt below??? private static interface FuncToTFunc<T> { Func<T> apply(FuncToTFunc<T> x); } BTW, what is "x" in the above? Also is Func define
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ProfHewitt
5y ago
Does the github Java code make use of recursion?
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ProfHewitt
5y ago
Thanks! Could you use your Java code to define Factorial?
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ProfHewitt
5y ago
Could you write this in Java?
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ProfHewitt
5y ago
Y Combinator does not work for strongly-typed programs because the definition is not strongly typed. Instead recursion must be added as an additional primitive to the lambda calculus. See https://papers.ssrn.com/abstract=3
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ProfHewitt
5y ago
Classical mathematical logic requires complete consistency. Discourse using empirical information inevitably involves some disagreement requiring robust inference. See the following article: https://papers.ssrn.com/abstract=
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